Charakterisierung der Dolichol‑Phosphat‑Mannosyltransferase 1, ein Enzym der Biosynthese von Glykosylphosphatidylinositolen im Einzeller Babesia microti

Als humane Babesiose bezeichnet man eine durch die Einzeller Babesia divergens und Babesia microti hervorgerufene Infektionskrankheit. Diese eukaryotischen Parasiten werden durch Zecken der Gattung Ixodes übertragen und verursachen Infektionen und Erkrankungen bei einer Vielzahl von Säugetieren, sowie auch beim Menschen. Neben akuten grippeähnlichen Symptomen sind auch latente Verläufe mit monatelanger a‑ oder oligosymptomatischer Parasitämie beschrieben worden. Die Diagnose erfolgt durch den Nachweis der intraerythrozytären Parasiten im Blutausstrich oder im Dicken Tropfen, wobei insbesondere bei geringer Parasitämie die Abgrenzung von einer Malaria sehr schwierig sein kann. Das Enzym Dolichol-Phosphat-Mannosyltransferase 1 (DPM1) ist ein ubiquitär und evolutionär stark konserviertes Enzym und bildet ein essentielles Substrat (Dolichol-Phosphat-Mannose), was für die Biosynthese von Glykosylphosphatidylinositolen (GPIs) im endoplasmatischen Retikulum (ER) unentbehrlich ist. In dieser Arbeit wurde das Protein DPM1 von Babesia microti (B. microti) zu dem bislang nur wenige Informationen vorliegen, hinsichtlich seiner evolutionären Konservierung und seiner genetischen Eigenschaften mithilfe molekularbiologischer und bioinformatischer Techniken in systematischen Schritten charakterisiert. Es konnte gezeigt werden, dass sich DMP1 aus Babesia microti im Vergleich zu einer Vielzahl anderer Organismen unterscheidet. Mittels bioinformatischer Analysen von DPM1 aus Babesia microti, konnte anhand eines phylogenetischen Stammbaums gezeigt werden, dass es sich in puncto Hydrophobizität, vom Vorhandensein von weiteren Hilfsproteinen der DPM-Familie, einer GPI‑Verankerung sowie von Signalpeptidspaltungsstellen von DPM1 der verglichenen Organismen unterscheidet. Insbesondere zu DPM1 aus der Hefe Saccharomyces cerevisiae (S. cerevisiae) bestehen relevante biochemische Unterschiede. Es konnte dennoch mithilfe molekularbiologischer Klonierungstechniken die funktionelle Komplementation von DPM1 in der DPM1‑defizienten‑S. cerevisiae-Mutante, für die DPM1 essentiell ist, mit parasitischem DPM1 nachgewiesen werden. Das zeigt die artunabhängige evolutionäre Konservierung dieses Proteins sowie dessen funktionelle Austauschbarkeit

Novel Insights into the Pathophysiology of Chagas\u27 Cardiomyopathy

The protozoan hemoflagellate Trypanosoma cruzi (T. cruzi) is the etiologic agent of the zoonotic Chagas’ disease that affects approximately six to seven million people in Central and South America, causing dilated cardiomyopathy and megavisceral disease. Although Chagas’ disease is the leading cause of heart failure in Latin America among people living in poverty and places an immense socioeconomic burden on society, it is still currently classified as a neglected tropical disease (NTD). The disease is typically transmitted by reduviid bugs or orally by contaminated food, while the transmission of parasitic organisms by other routes such as blood transfusion, organ transplantation, and transplacental infection is relatively rare. Given the wide cellular tropism infecting virtually all nucleated cells, the protozoan is able to persist asymptomatically for decades until ultimately causing organ-specific symptoms of chronic Chagas’ disease such as chronic heart failure. The acute phase of the disease triggers an immune response that often does not restrict the dissemination of the parasite and may cause skin lesions, fever, enlarged lymph nodes, pallor, swelling, and abdominal and chest pain. Despite recent advances in our knowledge about the pathogenesis of this disease, the complex host-parasite interactions are not completely understood and, in particular, the persistence of parasites in host cells for such a long time remains largely undefined. In this book chapter, we focus on the pathophysiology of American trypanosomiasis and emphasize the role of host-specific transcription factors executing antiparasitic immune reactions

Regulation of lipid metabolism-related gene expression in whole blood cells of normo- and dyslipidemic men after fish oil supplementation

Background: Beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on the lipid levels of dyslipidemic subjects are widely described in the literature. However, the underlying molecular mechanisms are largely unknown. The aim of this study was to investigate the effects of n-3 PUFAs on the expression of lipid metabolism-related genes in normo- and dyslipidemic men to unveil potential genes and pathways affecting lipid metabolism. Methods. Ten normo- and ten dyslipidemic men were supplemented for twelve weeks with six fish oil capsules per day, providing 1.14 g docosahexaenoic acid and 1.56 g eicosapentaenoic acid. The gene expression levels were determined by whole genome microarray analysis and quantitative real-time polymerase chain reaction. Results: Several transcription factors (peroxisome proliferator-activated receptor α (PPARα), retinoid X receptor (RXR) α, RXRγ, hepatic nuclear factor (HNF) 6, and HNF1ß) as well as other genes related to triacylglycerol (TG) synthesis or high-density lipoprotein (HDL-C) and cholesterol metabolism (phospholipids transfer protein, ATP-binding cassette sub-family G member 5, 2-acylglycerol O-acyltransferase (MOGAT) 3, MOGAT2, diacylglycerol O-acyltransferase 1, sterol O-acyltransferase 1, apolipoprotein CII, and low-density lipoprotein receptor) were regulated after n-3 PUFA supplementation, especially in dyslipidemic men. Conclusion: Gene expression analyses revealed several possible molecular pathways by which n-3 PUFAs lower the TG level and increase the HDL-C and low-density lipoprotein level, whereupon the regulation of PPARα appear to play a central role. Trial registration. ClinicalTrials.gov (ID: NCT01089231).BMB

Beer Brand Word-of-Mouth Drivers in Colombia: A Qualitative Exploration

This paper explores which motivational drivers incline consumers to engage in word-of-mouth (WOM) communication within the Colombian beer market, forecast to be among the most important beer markets during the coming years. Colombian consumers are primarily influenced by recommendations from friends and family and are therefore more likely to adopt new products due to WOM rather than mass communication. Yet marketers still have little knowledge of how to manage WOM effectively, especially in the Latin America region. Consequently, the authors adopt a qualitative research method conducting semi-structured interviews with fifteen Colombian beer market mavens aimed at exploring which motivational drivers cause consumers to engage in WOM. Twelve motivational drivers were found for WOM about beer brands. Of these, two were found to be partially important, and three appeared to be necessary. The findings of this study propose a number of recommendations to be made for enhancing motivational drivers to generate more WOM. The findings of the study could be used to develop a quantitative measurement identifying which of the motivational drivers have the most influence on Colombian consumers to engage in WOM. This research could assist brewing businesses to internationalise into the Colombian beer market and to achieve competitive advantage

Diagnostic Performance of Kwak, EU, ACR, and Korean TIRADS as Well as ATA Guidelines for the Ultrasound Risk Stratification of Non-Autonomously Functioning Thyroid Nodules in a Region with Long History of Iodine Deficiency: A German Multicenter Trial

Simple Summary In Germany, thyroid nodules can be detected by ultrasound examinations in over 30% of the adult population, mainly as a result of prolonged nutritive iodine deficiency. Although only a small proportion of the nodules are malignant, it is important to have a reliable examination method that not only can detect these few thyroid carcinomas with a high degree of certainty, but also not be unnecessarily invasive for the much larger number of benign nodules. Ultrasound is the method of choice, and ultrasound-based risk stratification systems are important tools in clinical care. However, many different systems have been introduced within the last decade. The aim of this study was to evaluate five common ultrasound risk stratification systems for their diagnostic accuracy of thyroid nodules from an area with long history of iodine deficiency. Abstract Germany has a long history of insufficient iodine supply and thyroid nodules occur in over 30% of the adult population, the vast majority of which are benign. Non-invasive diagnostics remain challenging, and ultrasound-based risk stratification systems are essential for selecting lesions requiring further clarification. However, no recommendation can yet be made about which system performs the best for iodine deficiency areas. In a German multicenter approach, 1211 thyroid nodules from 849 consecutive patients with cytological or histopathological results were enrolled. Scintigraphically hyperfunctioning lesions were excluded. Ultrasound features were prospectively recorded, and the resulting classifications according to five risk stratification systems were retrospectively determined. Observations determined 1022 benign and 189 malignant lesions. The diagnostic accuracies were 0.79, 0.78, 0.70, 0.82, and 0.79 for Kwak Thyroid Imaging Reporting and Data System (Kwak-TIRADS), American College of Radiology (ACR) TI-RADS, European Thyroid Association (EU)-TIRADS, Korean-TIRADS, and American Thyroid Association (ATA) Guidelines, respectively. Receiver Operating Curves revealed Areas under the Curve of 0.803, 0.795, 0.800, 0.805, and 0.801, respectively. According to the ATA Guidelines, 135 thyroid nodules (11.1%) could not be classified. Kwak-TIRADS, ACR TI-RADS, and Korean-TIRADS outperformed EU-TIRADS and ATA Guidelines and therefore can be primarily recommended for non-autonomously functioning lesions in areas with a history of iodine deficiency

Introducing a pole concept for nodule growth in the thyroid gland: taller-than-wide shape, frequency, location and risk of malignancy of thyroid nodules in an area with iodine deficiency

Purpose : (i) To examine the criterion taller-than-wide (TTW) for the sonographic assessment of thyroid nodules in areas of iodine deficiency in terms of frequency, anatomical distribution within the thyroid gland and risk of malignancy. (ii) To develop a model for nodule growth in the thyroid gland. Methods: German multicenter study consisting of two parts. In the prospective part, thyroid nodules were sonographically measured in all three dimensions, location within the thyroid gland and contact to a protrusion-like formation (horn) in the dorsal position of thyroid gland was noted. In addition, further sonographic features such as the composition, echogenity, margins and calcifications were investigated. All nodules from the prospective part were assessed for malignancy as part of clinical routine at the decision of the treating physician adhering to institutionally based algorithms. In the retrospective part, only nodules with fine needle aspiration and/or histology were included. The risk of malignancy in TTW nodules was determined by correlating them with cyotological and histological results. Results: Prospective part: out of 441 consecutively evaluated thyroid nodules, 6 were found to be malignant (1.4%, 95% CI 0.6–2.7%). Among the 74 TTW nodules (17%), 1 was malignant (1%, 95% CI 0–4%). TTW nodules were more often located in the dorsal half of the thyroid than non-TTW nodules (factor 2.3, p = 0.01, 95% CI 2.1–2.5) and more often located in close proximity to a horn than non-TTW nodules (factor 3.0, p = 0.01, 95% CI 2.4–3.8). Retrospective part: out of 1315 histologically and/or cytologically confirmed thyroid nodules, 163 TTW nodules were retrieved and retrospectively analyzed. A TTW nodule was 1.7 times more often benign when it was dorsal (95% CI 1.1–2.5) and 2.5 times more often benign when it was associated with a horn (95% CI 1.2–5.3). The overall probability of malignancy for TTW nodules was 38% (95% CI 30–46%) in this highly preselected patient group. Conclusion: TTW nodules are common in iodine deficient areas. They are often located in the dorsal half of the thyroid gland and are frequently associated with a dorsal protrusion-like formation (horn) of the thyroid. Obviously, the shape of benign nodules follows distinct anatomical preconditions within the thyroid gland. The frequency of TTW nodules and their predominant benignity can be explained by a pole concept of goiter growth. The difference between the low malignancy risk of TTW nodules found on a prospective basis and the high risk found retrospectively may be the result of a positive preselection in the latter

Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions’ continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios

Identification and characterization of myocardial metastases in neuroendocrine tumor patients using 68Ga-DOTATATE PET-CT

Background: Focal 68Ga-DOTATATE PET lesions within the myocardium of neuroendocrine tumor (NET) patients are observed in clinical practice. We determined the frequency and characteristics of lesions that are consistent with cardiac metastasis and assessed the lesion detection rate of conventional imaging. Methods: 629 patients who underwent 68Ga-DOTATATE PET-CT at a supraregional comprehensive cancer center on NET were included from a consecutive registry. Inclusion criteria were: (1) focal 68Ga-DOTATATE tracer uptake within the myocardium in more than two sequential PET exams, and (2) contrast-enhanced CT. To determine the diagnostic accuracy of conventional CT imaging, a case-control cohort with a ratio of 1:3 was used. PET and CT were independently analyzed by two blinded readers. Cohen's K was assessed for interreader agreement Descriptive statistics were applied for frequencies and characteristics and group comparisons were analyzed using the Fisher's exact test. Results: The prevalence of myocardial metastases related to the registry was 2.4% (15 of 629 NET patients fulfilling the inclusion criteria), for a total of 21 myocardial 68Ga-DOTATATE foci detected. Myocardial lesions were most frequently located in the left ventricle (43%) and the septum (43%). No patient demonstrated a pericardial effusion. Patients with myocardial metastases did not differ in demographics, tumor grading, disease stage or circulating tumor markers compared to the overall registry (all p > 0.05). Higher Ki67-Indices were observed (p = 0.049) for patients with myocardial metastases. Interreader agreement for PET assessment was excellent (Cohen's K = 1.0). CT reading showed a sensitivity of 19% (95% confidence interval: 6-43%) at a specificity of 100% (95% confidence interval: 90-100%). Conclusions: 68Ga-DOTATATE PET enables detection of myocardial metastatic lesions in NET patients. In contrast, standard morphologic CT imaging provides very limited sensitivity

A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

Background: Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods: 50MBWtest occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results: Using qualitative criteria, 46/168 trials were rejected: 16.6%were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53– 0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions: The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes